This invention relates to explosives and more particularly to polynitroorganic explosives.
E. F. Witucki and M. B. Frankel, J. Chem. and Eng. Data, 24, 382 (1979), reported the preparation of 2-fluoro-2,2-dinitroethyl pentafluorothioacetate from 2-fluoro-2,2-dinitroethanol and pentafluorothioacetyl chloride. The acetyl chloride was chosen as the --SF.sub.5 starting material because of its availability from SF.sub.5 Cl and ketene. E. F. Witucki and M. B. Frankel, Rockwell International UCRL report 13809 (1978), describe 2-fluoro-2,2-dinitroethyl pentafluorothioacetate as a dense, thermally stable, insensitive liquid.
We have recently prepared other polynitroaliphatic esters of pentafluorothioacetic acid (using the Witucki et al. method) and have found them to be liquids or very low melting solids. For instance:
______________________________________ Ester m.p. (.degree.C.) ______________________________________ 2,2-dinitropropyl pentafluorothioacetate 22 3-fluoro-3,3-dinitropropyl pentafluorothioacetate 28 3,3,3-trinitropropyl pentafluorothioacetate 32 ______________________________________
Thus, like the prior art 2-fluoro-2,2-dinitroethyl pentafluorothioacetate, these novel polynitroaliphatic esters of pentafluorothioacetic acid are limited to liquids or very low melting solids. This is a disadvantage because many applications require high melting solid explosives.
Therefore, it would be desirable to have available higher melting pentafluorothio (SF.sub.5) explosives in order to provide a greater choice of physical properties for these types of compounds.